A track trencher excavation machine, shown in FIGS. 1 and 2, typically includes an engine 36 coupled to a right track drive 32 and a left track drive 34 which together comprise the tractor portion 45 of the track trencher 30. An attachment 46, usually coupled to the front of the tractor portion 45, typically performs a specific type of excavating operation.
A ditcher chain 50 is often employed to dig relatively large trenches at an appreciable rate. The ditcher chain 50 generally remains above the ground in a transport configuration 56 when maneuvering the trencher 30 around the work site. During excavation, the ditcher chain 50 is lowered, penetrates the ground, and excavates a trench at the desired depth and speed while in a trenching configuration 58. Another popular trenching attachment is termed a rock wheel in the art, shown in FIG. 3, and may be controlled in a manner similar to that of the ditcher chain 50.
Controlling a track trencher 30 using a prior art control scheme generally requires an operator to manipulate various levers, switches, and knobs in order to operate the track trencher 30 both safely and efficiently. A high degree of skill is typically required on the part of the operator who must continuously monitor and adjust the propulsion and steering of the tractor portion 45, as well as the operation of the attachment 46, when operating the track trencher 30 in one or more travel modes, including particularly a trench mode and a transport mode. Maintaining optimum track trencher performance using prior art propulsion and steering controls during both excavation and transport is generally considered an exacting and fatiguing task.
FIG. 4 is an illustration of a conventional control panel 62 of a track trencher 30. Propulsion and steering of a track trencher 30 when operating in a transport mode is generally controlled by manipulating the left and right track levers 64 and 66 which respectively control actuation of the left and right track drives 34 and 32. Moving the right track lever 66 forward, for example, generally causes the right track drive 32 to operate in a forward direction and, depending on the relative velocity of the left track drive 34, steers the track trencher 30 to move in either a left or right direction. Reversing the right track drive 32 is generally accomplished by pulling the right track lever 66 backwards, thereby causing the right track drive 32 to operate in a reverse direction.
Propulsion of the left track drive 34 is accomplished in substantially the same manner as that previously described with regard to the right track drive 32. Thus, both propulsion and steering are controlled by the prior art track levers 64 and 66 of a track trencher 30. Moreover, propulsion and steering control of the right track drive 32 is completely independent from that of the left track drive 34.
It is often desirable to maintain the engine 36 at a constant, optimum output level during excavation which, in turn, allows the trenching attachment 46 to operate at an optimum trenching output level. The prior art control panel shown in FIG. 4 includes a plurality of controls and switches, including a speed range switch 74, RPM knob 76, steering trim knob 78, and propel trim knob 80. All of these switches and knobs must typically be adjusted during normal trenching operation to maintain the engine at the desired engine output level when encountering variable attachment 46 loading, and to steer the track trencher 30 in a desired direction. Additionally, the right and left pump potentiometers 84 and 82 typically require adjustment and readjustment to equilibrate the operational characteristics of the left and right pumps 38 and 40.
The speed range switch 74, for example, is typically adjustable between a low, medium, and high switch setting. The particular speed range setting is generally determined by a number of factors during excavation, including the desired trenching speed and the type of soil being subject to excavation. A high speed range switch 74 setting is generally appropriate for trenching through softer soil, whereby the track trencher 30 will typically operate at a relatively high speed due to a relatively low level of loading on the trenching attachment 46. Upon encountering more compacted soil, such as concrete, the loading on the trenching attachment 46, typically powered by the engine 36, will increase, thereby resulting in a corresponding reduction in the speed of the track trencher 30.
The operator must generally react quickly to such changes in engine 36 loading typically by first determining the appropriate switch to adjust, and then the degree of switch adjustment. Typically, minor propulsion modifications are made by adjusting the propel trim knob 80. Moderate changes to the propulsion level of the track trencher 30 are effectuated by adjusting the RPM knob 76. A major modification to the propulsion level of the track trencher 30 is typically accomplished by switching the speed range switch 74 from a high setting to either a medium or low setting, and once again adjusting the propel trim knob 80 and RPM knob 76 in order to avoid stalling out the engine 36.
A track trencher excavation machine typically employs one or more sensors that monitor various physical parameters of the machine. The information gathered from the sensors is generally used to moderate a particular machine function, or to provide the operator with information typically by transducing a sensor signal for communication to one or more analog display instruments, such as a tachometer 72, for example. The information communicated to an operator by employing a plurality of analog display instruments must generally be interpreted by a skilled operator in order to assess whether the track trencher is operating within acceptable performance and safety margins.
There is a desire among the manufacturers of track trenchers to minimize the difficulty of operating a track trencher both in a transport mode and, more particularly, in a trench mode. There exists a further desire to reduce the substantial amount of time currently required to adequately train a track trencher operator. Additionally, there continues to exist in the excavation equipment manufacturing community a keenly felt need to enhance the means of communicating operational, diagnostic, and safety-related information to the operator during track trencher operation. The present invention fulfills these needs.